import turtle

def draw_empty_circle(pen, x, y, radius):
    pen.penup()
    pen.goto(x, y - radius)
    pen.pendown()
    pen.color('black')  # 设置边框颜色为黑色
    pen.fillcolor('white')  # 设置填充颜色为空白
    pen.pensize(2)  # 设置边框宽度为2
    pen.circle(radius)


def draw_filled_circle(pen, x, y, radius):
    pen.penup()
    pen.goto(x, y - radius)
    pen.pendown()
    pen.color('black')  # 设置边框颜色为黑色
    pen.fillcolor('black')  # 设置填充颜色为黑色
    pen.begin_fill()  # 开始填充
    pen.circle(radius)
    pen.end_fill()  # 结束填充

canvas = turtle.Screen()
pen = turtle.Turtle()

# 调用绘制实心圆的函数
draw_filled_circle(pen, 100, 0, 50)

# 调用绘制空心圆的函数
draw_empty_circle(pen, 0, 0, 50)

turtle.done()
